Four-wheel drive for power vehicles



May 26, 1925. 1,539,417

` F. HUBER FOUR-WHEEL DRIVE FOR POWER VEHICLES Filed Apriil A16, 1924 l l. da

Patented May 26, i925.

FRTZ HUBER, F MANNHTEM, GERMANY, ASSIGNOR T0 HENRICH LANE, 0F MANN- BADEN, GEPRA'NY, .A COPARTNERSHIP.

EUHR-'WHEEL DENTE- hOR POWER'VEHCLES.

Application filed April 1G, i924. @Serial No. 706,8D4.

To {aZZ whom it may concern:

Be it known that l, Fnrrz HUBER, a citizen of Germany, residing in the city ot Mannheim, Baden, Germany, have invented certain new and useful improvements in a llour-lifheel Drive for Power Vehicles, ot which the following is a specification.

ln the tour-wheel drive of power vehicles the conditions are frequently such that the rear and the iront wheels rotate at different speeds. So lar as such difference is due to a difference ot wheel diameters, the diiiticulty can easily be remedied by the adoption oil a suitable gear ratio. lint when traveling in curves or in turning, i'or example, a difiercnce in the rate or revolution will always be produced in case the tulcrum about which the two axles are detlected or set relative one Ito the other by the steering gear does not lie xactly in the system-center. Thus, it the ulcruin'is located at a point nearer the rear wheels then these wheels will turn Yfaster than the liront. wheels, and vice versa.

ln order to oobviate this difticulty, it has heretofore been proposed to provide the 'iront wheels with a ratchet-wheel drive and the r ir wheels, on the other hand with a and partly in section,

embodiment of my improved drive as is fixed drive. But in this case the wheel dianr eters must be very accurately proportioned to the gear ratio, and even then the front and rear wheels will be driven at equal peripheral speed only on relatively slight curves. rl`he iront wheels can run tree only on still smaller curves, while on all sharper curves the same diliiculties will nevertheless be experienced.

li/l present invention, by which l have eliminated all trouble due to a difference in the rate of revolution of the wheels in a 'tour-wheel drive, consists, broadly, in the interposing of a diiierential gear both between the two 'front and between the two rear' running wheels and in driving one of 'these two diderential gears by means of a coastermounted or tree-wheel gear.

ylfhe invention is shown, by way oi' illustration, in the accompanying drawings, whereinl Fig. i is a view showing, partly iniplan so much ot one specific necessary for a full understandingl thereof, the section through both ditierentials being taken upon the line A B G of Fig. 2'; Fig.

2 is a sectional view of the upper di'lierential, on the line D E of lFig. l and looking in the direction of the arrow ll; and Fig. 3 is a view showing, in side elevation and detached, the coasterdnounted or iice-\\'lieel gear incorporated in the lower diiierential.- Referring to the drawings, o indicates one, preferably the iront, axle ot the vehicle and b the other axle, both dead ait'les, upon which rotate the running wheels al (z2 and b1 b2, respectively. r)The running wheels carry internal spur gears c1 c2 and Z1 (I2 with which mesh the pinions e1 f1 g1 71,1 ot the dii'- ferential shafts c f g h, which shafts have lixed on their inner ends, rcspectiif'cly, thc spur master gears e2 f2 g2 h2.

Mounted tree on the shaft z. is a flange c' which is secured by screws or otherwise both tothe bevel gear and tothe diii'erential case Z; and upon bolts m m1 m2 ma, fixed at one end in the flange and at the other end in the bottom wall ot the case, rotate two pairs of spur pinions n nl and n? n.3, fn. and 'a3 in engagement with the master gear g2 and nl and n? in engagement with the master gear M2, which as usual are wider than the gears so that the two pinions oi". each pair will overlap each other and mesh together. v

Accordingly, when the bevel gear l, is driven by the bevel gear or, it will cause the flange 'i and case Zto rotate and to carry with them the four pinions which in turn, the running wheels b1 b2 oliering vequal resistance, will drive the master gears and consequently the running speed. lf, however, one of the running wheels, b1 Jfor example, offers a greater resistence to the propelling effort than does the other, then pinions n n3, actuated by the gear g2, will turn 0n their'axes and in so doing will cause pinions al 11,2 to turn and wheels at the same thereby impart 'a higher speed to the gear k2 and to the running wheel b2.

The epicyclic gearing which is associated with the shafts e and f is of th'e same general construction as that above described. But here a coaster or free-wheel connection is interposed between the bevel gear icl and the 'flange 1, the arrangement being as follows: The flange-i1, carrying integral therewith the bush 2, is secured byA bolts 3 to a coaster disk p and counter disk q. The bevel gear k1 is mounted to rotate upon the lil() coaster disk p and carries, set in a suitable recess or recesses provided for the purpose in one of its sides, the pawls p2 which are yieldably held by springs p3 in the tooth notches p1 formed in the periphery ofthe disk. A sprocket r, through which the pro- `peiling power is transmitted from the en- With, the bevel gear k1 is caused to rotate, by

the engagen'ient `of its pawls p2 withthe toothed end of the notches in the coaster disk, and in turning transmits its rotary movement to the bevel gear 01, the shaft sections s s1, the bevel gear o, and thence to the differential gear ofthe shafts g k in the manner herein-above described. The shaft. sections s s1 are connected, at the point t, by a Cardan or other suitable universal joint, which needs no description. When traveling on a curve, the arc described, and conse quently the length of the ath covered, by

the pair'of running whees a1 a2,wil1 be smaller than that described by the running wheels b1 b2. The latter pair of wheels, therefore, must necessarily revolve at a greater speed than the first pair, and hence the bevel gear xl simply draws its pawls from the notches and overruns the coaster disk. |The result is that, the wheels 151v b2 running free of the drive, a grinding of these wheels on the ground is prevented and the entire gearing system is relieved of much of the stress to which it otherwise would have been subjected.

It is to be understood that any other type of differential gear may be substituted for the one herein specifically shown and described and that the invention may `be further modified in its various details.

lVhat I claim as new, and desire to secure byLetters Patent, is-

1. A four-wheel drive for power vehicles in which two differential gears driving each a wheel pair are operatively connected through a free-wheel connection incorporated in one differential gear and said d1fferential gear 1s drivenfromi the engine and in turn drives the other wheel connection.

2. A four-wheel drive for power vehicles comprising a differential gear which is driven from the engine and drives one of the two pairs of running wheels and a second differential gear which is driven from the engine through a free-wheel gear housed through said freewithin the hcus'ingof' the first differential differential gear which is driven from the.

first through a free-wheel gear housed within the housing of said first differential gear and in turn drives a divided shaft geared to the wheels of the second wheel pair.

4. In a four-wheel drive for power vehicles in which the two pairs of running wheels describe different arcs when traveling oncurves, the combination of a differential ear which is driven from the engine and drives that pair of therunning wheels which on curves describes the smaller arc and a second differential gear which is driven from amember of the first differential gear through a free-wheel connection and in turn drives the other pair of running wheels.

5. A four-wheel drive for power vehicles in vwhich the fulcrum is located nearer one wheel pair than the other and the two wheel pairs will consequently have a different average peripherial speed, comprising two differ'- ential gears one of which is driven from the engine with a fixed drive and drives the wheel pair having the lesser average peri heral speed and the other is driven throu 1 a free-wheel connection and drives the W ieel 100 pair having the greater average peripheral speed.

DR. FRITZ HUBER. Witnesses:

HELMUT LINDNER, VALENTIN Wnnnnps..

ear which is driven from the 

